I was wondering that too. I was also thinking it could be some sort of electrical connector or socket.I'm wondering if that piece inside of the hanger is a model kit part.
The part on that replica is not correct.
No one has found the real part as of yet..
The whole assembly on the helmet (flex hose/conduit, flange housing, and internal connector) looks like some sort of push-on electrical (dis)connector.I was wondering that too. I was also thinking it could be some sort of electrical connector or socket.
That part on top of the UZI look a heck of a lot like a G-clamp. You can clearly make out the thread and the handle at the back to tighten the clamp.
It's one that can be fixed to benchtop, or it could be part of a jig for cutting mitres or something similar.
This is the best I could find....
Ed